This invention relates generally to waterbeds, and more particularly to apparatus for supporting the perimeter of a fluid-filled flexible bladder of a waterbed mattress.
Floatation sleep systems, commonly referred to as waterbeds, have become a popular alternative to conventional bedding. This is because waterbeds provide totally balanced body support which has been found to induce a superior state of relaxation. There are four common configurations for waterbeds in use today.
The first mattress configuration includes a free-standing, flexible bladder filled with liquid, such as water. Since the free-standing bladder is flexible in all directions, it must be of a bottom-to-top dimension (height) to prevent "bottoming out" when a body is supported thereon. Such dimension makes getting on and off the mattress awkward, and the flexible side walls make sitting on the edge difficult.
In the second mattress configuration, a frame is located about the lateral marginal edges of the flexible bladder. The frame supports the side walls of the bladder so as to maintain a desired height to prevent bottoming out. However, the side walls of the frame still make getting on and off the mattress, or sitting on the edge, uncomfortable. The third mattress configuration was devised to overcome this problem. In the third configuration, a compressible medium, such as foam, surrounds at least a portion of the lateral marginal edges of the flexible bladder to form the frame. (See for example, U.S. Pat. No. 3,840,921, issued Oct. 15, 1974, in the name of Labianco.) While this configuration solves the comfort problem associated with the edges of previous configurations, it adds considerably to the cost and complexity of assembly of the overall floatation system.
In order to keep down the cost and facilitate assembly yet provide edge comfort, a forth mattress configuration utilizes compressible air chambers in the lateral marginal edges of the flexible bladder. (See, for example, U.S. Pat. No. 4,079,473, issued Mar. 21, 1978, in the name of Phillips.) The air chambers provide edge comfort and maintain the mattress at a desired height, but are subject to deterioration of the seals between the air and liquid chambers and require replacement of the entire mattress when the air chambers are breached (by liquid or by external puncturing). Accordingly, in my U.S. Pat. No. 4,181,990, issued Jan. 8, 1980, I proposed a modification of this forth mattress configuration in which sleeves are attached to the lateral marginal edges of the flexible bladder. The sleeves slidably receive self-contained air (or foam) chambers to support the sides of the bladder and provide edge comfort. These self-contained chambers are not effected by the liquid in the bladder, and can be individually replaced if punctured so that the entire mattress need not be replaced. Another modification to the forth mattress configuration has been set forth in my copending U.S. patent application Ser. No. 121,281 filed Feb. 13, 1980, now abandoned. In this modification, a liner for containing any fluid escaping from the waterbed mattress removably receives the self-contained compressible chambers.